textproduct: Albany

WHAT HAS CHANGED

The latest outlook from the Storm Prediction Center had expanded the slight risk northward into Ulster, Dutchess and Litchfield counties for this afternoon and evening. No other significant changes at this time.

KEY MESSAGES

1) While most areas will see lower heat index values today, values remain high enough to continue posing an increased risk for heat-related illnesses for the mid Hudson Valley, southern Taconics and southern Litchfield County Connecticut.

2) Scattered thunderstorms this afternoon and evening may impact Outdoor 4th of July Events with cloud to ground lightning, gusty winds and heavy downpours. There is a Marginal to Slight Risk (Level 1 and 2 of 5) for severe thunderstorms for southern parts of the area.

3) A widespread rainfall is expected late Sunday through Monday with the heaviest amounts likely across the mid-Hudson Valley into Litchfield County, CT. Isolated flash flooding will be possible, especially within urban and poor drainage areas.

DISCUSSION

KEY MESSAGE 1...

A hot and humid afternoon continues across portions of the mid- Hudson Valley into southern Litchfield County, CT where heat index values have risen into the 95 to 100 degree range early this afternoon. The heat advisories will remain in effect until 7 pm this evening where there will be an increased risk for heat related illnesses. Elsewhere, a trend toward cooler and less humid conditions has begun.

KEY MESSAGE 2...

An approaching disturbance will bring scattered to numerous showers and thunderstorms this afternoon. Rain showers are ongoing north of I-90 early this afternoon. The better severe weather threat continues to be for areas mainly south of Interstate 90 where there is greater heating and instability present. There remains a marginal to slight risk for severe thunderstorms this afternoon into the evening. Damaging winds will be the primary risk with any thunderstorms that develop.

KEY MESSAGE 3...

Models are in good agreement for a widespread rainfall with some locally heavy rainfall later Sunday through Monday. A nearly stalled frontal boundary will be located south of the area with an area of low pressure tracking along the front. An area of rain and embedded thunderstorms will be spreading northward Sunday night and will be impacting the area for much of Monday and possibly continuing into Tuesday. Models continue to disagree on exactly where the northern edge of the steadiest precip will be, but southern areas certainly look to see the heaviest rainfall with this activity. Both the 00Z GFS and ECMWF suggest PWAT values will reach close to 2.00", which is about 2 STD above normal for early July. The latest NBM suggests total precip may reach 1" to 3" for Sunday night through Monday evening with the highest amounts in southern areas. It has dry recently and most areas could use some rainfall, but high rainfall rates and high rainfall totals may still lead to some localized issues, especially in urban and poor drainage areas. WPC now has a Marginal Risk for most of the area for the Day 3 Outlook, with the Slight Risk (Level 2 of 4) getting into far southern areas as well. Will continue to monitor model trends, but a wet and cooler Monday looks more likely, with some flooding concerns certainly on the table. River rises are expected but no river flooding concerns are expected at this time.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

Through 18z/Sunday...Current KENX radar shows some showers/convection moving down off Lake Ontario through the evening ahead of an approaching cold front. VFR conditions should mainly prevail across the terminals through the rest of the afternoon outside of some possible showers at KGFL, KALB, and KPOU over the next few hours. MVFR vis could occur and KALB and MVFR cigs could occur at KGFL with low level stratiform showers moving in from the northwest. Scattered thunderstorms are expected to develop around sunset with the best chance for more southern areas especially at KPOU between about 22z and 02z tonight reducing vis to IFR. KPSF could also see a thunderstorm tonight but confidence is lower that it will reach this far north, however if it does, vis could be lowered to MVFR. There is also a chance of patchy mist/fog occurring at KPOU and KPSF following the showers overnight resulting in periods of MVFR/IFR just before sunrise. By mid morning, all terminals should have returned to VFR as low clouds begin to move out with mainly broken to overcast mid and high level clouds through the end of the TAF period. West/northwest winds 6-11 kt with occasional gusts near 20 kt become light and variable overnight, however any thunderstorm that develops will have stronger winds with sustained speeds near 20 kt and gusts up to 40 kt possible. Winds then shift more easterly ranging from northeast to southeast near 5 kt into tomorrow morning.

Outlook...

Sunday Night: Moderate Operational Impact. Chance of SHRA. Monday: High Operational Impact. Likely SHRA...TSRA. Monday Night: High Operational Impact. Likely SHRA...TSRA. Tuesday: Moderate Operational Impact. Chance of SHRA...TSRA. Tuesday Night: Low Operational Impact. Slight Chance of SHRA. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...Heat Advisory until 7 PM EDT this evening for CTZ013. NY...Heat Advisory until 7 PM EDT this evening for NYZ059-060- 064>066. MA...None. VT...None.